In an automated data storage library, numerous storage slots, or cells, arrayed within the library are used to hold data storage media, such as magnetic tape cartridges or cassettes, or optical disk cartridges. The storage slots are typically arranged in planar or cylindrical arrays of rows and columns. A picker, furnished with one or more grippers, is a robotic device which moves along a guideway in a horizontal motion, or about a pivot in a rotary motion, and moves vertically to access the various storage slots with the gripper, and transports selected data storage media amongst the storage slots and one or more read/write stations. The operation of the picker is typically under the direct control of a library manager, which is a program in a data processing library controller typically situated in the library. The library controller is interconnected with one or more host computer systems, such as a mainframe or network computer, which issues commands to the library. The read/write station may be interconnected with the host(s) and, after a data storage medium is delivered to the station, typically searches for, and reads selected data from or writes data to the selected data storage media under the control of a host.
Libraries also typically contain input/output stations or ports through which an operator may pass one or more data storage media to be added to the storage array and through which the picker may pass data storage media to be removed from the data storage array. For example, in coassigned U.S. Pat. 5,731,926, Gallo et al., issued Mar. 24, 1998, "Convenience Input/Output Station" an input/output station uses an elevator to vertically translate a tape cartridge or a non-removable magazine containing several tape cartridges into or out of the library. The elevator is movable between two positions, a maximum vertical position above the top surface of the library and a minimum vertical position within the library. An operator adds cartridges to the library by placing them into the input/output station situated at its maximum vertical position. The elevator then lowers the cartridges into the library by moving to its minimum vertical position. The picker then removes the cartridges from the input/output station.
However, an input/output station for single groups of cartridges may be highly inefficient and unable to allow the import, export or exchange of selected groups of cartridges or other data storage media of the library in a reasonable amount of time. For example, should a failure of the picker occur, it would be advantageous to be able to rapidly export any selected group of the data storage media from the failing library and import them into a fully functioning library.